Bug#489006: have /boot on md0 (dm-raid1), but install grub to MBRs of both disks?

[Sven Mueller <sven@incase.de>]

Well, Subject basically says what I try:

I want to have
/boot on /dev/md0 (raid1, sda1+sdb1)
/ on /dev/md1 (also raid1, sda5/sdb5
swap, non-critical data on lvm on /dev/md2 (raid0, sda6/sdb6)

The Debian installer easily lets me create such a layout, even using
preseeding. However, grub (both legacy and grub2) fail to generate a
device mapping for md0, thus being unable to install grub.

In my opinion such a partition layout should either be impossible to
create with d-i (or at least generate a warning) or grub-pc should
support this setup. Especially since this sort of partitioning is an
example in the partman-raid (or was it partman-lvm?) documentation. Not
exactly the way I described it, but with /root on lvm on raid.

Regards,
Sven